Challenging growth–survival trade-off: a key for Acer negundo invasion in European floodplains?

2010 ◽  
Vol 40 (10) ◽  
pp. 1879-1886 ◽  
Author(s):  
Patrick Saccone ◽  
Jean-Jacques Brun ◽  
Richard Michalet
Keyword(s):  
Native Species ◽  
High Growth ◽  
Adaptive Plasticity ◽  
High Survival ◽  
Trade Off ◽  
Acer Negundo ◽  
Successional Species ◽  
Survival And Growth ◽  
Succession Theory ◽  
Better Than

We compared the performances of juvenile Acer negundo with those of native species to assess how this species has invaded intermediate habitats along European riparian successional gradients. In the middle Rhône floodplain (France), we measured survival and growth of transplants of the invasive and of three native tree species from contrasted successional status within forests and in experimental gaps and at three positions along a riparian gradient: (i) a highly disturbed Salix – Populus stand, (ii) a moderately disturbed stand dominated by the invasive Acer , and (iii) a mature Fraxinus community. Acer’s growth in the gaps was as high as that of the two native early-successional species, Salix and Populus, and higher than that of the native late-successional Fraxinus. In contrast, Acer survived as well in the shadiest understory conditions of the Fraxinus community as did Fraxinus and better than the two early-successional species. Inconsistent with the resource trade-off of succession theory, Acer showed both a high survival in the shade and a high growth in full light. This particular suite of traits shared with other invasive and native Acer species could be an example of adaptive plasticity that certainly represents an advantage to give it a competitive advantage over native species.

Transplantation of coral fragment, Acropora formosa (Scleractinia)

2014 ◽  
pp. 1
Author(s):  
Hanny Tioho ◽  
Maykel A.J Karauwan
Keyword(s):  
Fragment Size ◽  
Observation Time ◽  
Minimum Size ◽  
Average Growth Rate ◽  
Average Growth ◽  
Significant Difference ◽  
Acropora Formosa ◽  
Survival And Growth ◽  
One Way Anova ◽  
Better Than

The minimum size of coral transplants, Acropora formosa, was assessed to support their survival and growth. For this, 150 coral fragments of different sizes (5, 10, 15 cm) were transplanted close to the donor colony. Their survivorship and growth were observed for 12 months. At the end of the observation time, 90% of 15 cm-transplanted coral fragments survived, while the others (10cm and 5 cm) did 86% and 82% respectively. The average growth rate of 5 cm-coral fragments was 0.860 cm/month, while 10 and 15 cm-fragments were 0.984 cm/month and 1.108 cm/month respectively. One-way ANOVA showed that there was significant difference (p<0.05) among the three (5, 10, 15 cm) transplant initial sizes in which the longest fragment size tended to survive longer than the smaller one.  However, the smaller transplants grew better than the bigger one, 10.318 cm/year (206%) for 5 cm-transplant, 11.803 cm/year (118%) for 10 cm-transplant, and 13.299 cm/year (89%) for 15 cm-transplant, respectively. Ukuran minimal fragmen karang Acropora formosa yang ditransplantasi diduga untuk mendukung ketahanan hidup dan pertumbuhannya. Untuk itu, 150 fragmen karang ditransplantasi ke lokasi yang berdekatan dengan koloni induknya.  Ketahanan hidup dan pertumbuhan semua fragmen karang yang ditransplantasi diamati selama 12 bulan.  Pada akhir pengamatan, 90% dari fragmen karang berukuran 15 cm yang ditransplantasi dapat bertahan hidup, sedangkan yang lainnya (ukuran 10 cm dan 5 cm) masing-masing sebesar 86% dan 82%.  Rata-rata laju pertumbuhan fragmen karang dengan ukuran awal 5 cm adalah 0,860 cm/bulan, sedangkan ukuran fragmen 10 dan 15 cm masing-masing adalah 0,984 cm/bulan and 1,108 cm/bulan. ANOVA satu arah menunjukkan adanya perbedaan yang nyata (p<0.05) antara ketiga ukuran fragmen yang berbeda, di mana ukuran fragmen karang yang lebih panjang cenderung mempunyai ketahanan hidup yang lebih baik. Namun demikian, ukuran transplant yang lebih kecil memiliki pertumbuhan lebih baik dibandingkan dengan ukuran yang lebih besar, yakni10,318 cm/tahun (206%) untuk transplant berukuran 5 cm, 11,803 cm/tahun (118%) untuk 10 cm, dan 13,299 cm/tahun (89%) untuk ukuran 15 cm.

Making the most of individual differences in joint decisions

2018 ◽  
Author(s):  
Bahador Bahrami
Keyword(s):  
Decision Making ◽  
Direct Evidence ◽  
Cross Cultural ◽  
Collective Decision Making ◽  
Wisdom Of Crowds ◽  
Trade Off ◽  
Adaptive Value ◽  
Joint Decisions ◽  
Cultural Data ◽  
Better Than

Evidence for and against the idea that “two heads are better than one” is abundant. This chapter considers the contextual conditions and social norms that predict madness or wisdom of crowds to identify the adaptive value of collective decision-making beyond increased accuracy. Similarity of competence among members of a collective impacts collective accuracy, but interacting individuals often seem to operate under the assumption that they are equally competent even when direct evidence suggest the opposite and dyadic performance suffers. Cross-cultural data from Iran, China, and Denmark support this assumption of similarity (i.e., equality bias) as a sensible heuristic that works most of the time and simplifies social interaction. Crowds often trade off accuracy for other collective benefits such as diffusion of responsibility and reduction of regret. Consequently, two heads are sometimes better than one, but no-one holds the collective accountable, not even for the most disastrous of outcomes.

scholarly journals The aerodynamic puzzle of nasalized fricatives: Aerodynamic and perceptual evidence from Scottish Gaelic

2015 ◽  
Vol 6 (2) ◽  
Author(s):  
Natasha Warner ◽  
Daniel Brenner ◽  
Jessamyn Schertz ◽  
Andrew Carnie ◽  
Muriel Fisher ◽  
...  
Keyword(s):  
Scottish Gaelic ◽  
Trade Off ◽  
Instrumental Data ◽  
The World ◽  
Perceptual Evidence ◽  
Better Than ◽  
Do So

AbstractScottish Gaelic is sometimes described as having nasalized fricatives (/ṽ/ distinctively, and [f̃, x̃, h̃], etc. through assimilation). However, there are claims that it is not aerodynamically possible to open the velum for nasalization while maintaining frication noise. We present aerodynamic data from 14 native Scottish Gaelic speakers to determine how the posited nasalized fricatives in this language are realized. Most tokens demonstrate loss of nasalization, but nasalization does occur in some contexts without aerodynamic conflict, e.g., nasalization with the consonant realized as an approximant, nasalization of [h̃], nasalization on the preceding vowel, or sequential frication and nasalization. Furthermore, a very few tokens do contain simultaneous nasalization and frication with a trade-off in airflow. We also present perceptual evidence showing that Gaelic listeners can hear this distinction slightly better than chance. Thus, instrumental data from one of the few languages in the world described as having nasalized fricatives confirms that the claimed sounds are not made by producing strong nasalization concurrently with clear frication noise. Furthermore, although speakers most often neutralize the nasalization, when they maintain it, they do so through a variety of phonetic mechanisms, even within a single language.

What does Brazil know about the origin and uses of tree species employed in the housing sector? Perspectives on available species, origin and current challenges

2021 ◽  
Vol 23 (3) ◽  
pp. 392-404
Author(s):  
V. De Araujo ◽  
J. Vasconcelos ◽  
M. Gava ◽  
A. Christoforo ◽  
F. Lahr ◽  
...  
Keyword(s):  
Native Species ◽  
Eucalyptus Species ◽  
Housing Sector ◽  
Construction Sector ◽  
Foreign Markets ◽  
Product Certification ◽  
Face To Face ◽  
Species Origin ◽  
Corporate Websites ◽  
Better Than

Timber consumption is a complex discussion for the industry, in part because the issue has been marked by doubts about lineage and origin. This paper aimed to identify challenges related to species, origins and wood use in the Brazilian construction sector. Searches on corporate websites and face-to-face interviews were used to identify involvement by species and origin in the domestic production of timber for housing. Relevant results were obtained for both methods since their margins of error were low. Forty exotic and nine native species were revealed to contribute significantly to the construction sector. 'Grapia' and 'Angelim pedra' native woods and eight eucalypt and pine species were shown to be the most popular through both methodologies. Pine timber was found to be in greater demand than that of Eucalyptus species. Despite some lack of clarity relating to the origin of certain species, the sector's status was better than expected. However, it still requires assertive actions to increase the use of legalized wood in order to favour product certification and integration into foreign markets.

COMPUTING THE RUPTURE DEGREE IN COMPOSITE GRAPHS

2010 ◽  
Vol 21 (03) ◽  
pp. 311-319 ◽  
Author(s):  
AYSUN AYTAC ◽  
ZEYNEP NIHAN ODABAS
Keyword(s):  
Complete Graph ◽  
Connected Graph ◽  
The Other ◽  
Trade Off ◽  
Number Of Components ◽  
Np Complete ◽  
Work Done ◽  
Better Than

The rupture degree of an incomplete connected graph G is defined by [Formula: see text] where w(G - S) is the number of components of G - S and m(G - S) is the order of a largest component of G - S. For the complete graph Kn, rupture degree is defined as 1 - n. This parameter can be used to measure the vulnerability of a graph. Rupture degree can reflect the vulnerability of graphs better than or independent of the other parameters. To some extent, it represents a trade-off between the amount of work done to damage the network and how badly the network is damaged. Computing the rupture degree of a graph is NP-complete. In this paper, we give formulas for the rupture degree of composition of some special graphs and we consider the relationships between the rupture degree and other vulnerability parameters.

scholarly journals Does Public Service Television Really Give Consumers Less Good Value for Money than the Rest of the Market?

2018 ◽  
Author(s):  
Patrick Barwise
Keyword(s):  
Public Service ◽  
Policy Implication ◽  
Value For Money ◽  
Trade Off ◽  
The Public ◽  
Consumer Value ◽  
Consumer Benefits ◽  
The Uk ◽  
Tv Commercial ◽  
Better Than

This chapter explores the assumption that public service television (PST), i.e. BBC TV, commercial public service broadcasters (PSBs), and non-PSBs, offers less consumer value for money than the rest of the market in the UK; that the only continuing rationale for PST rests on citizen concerns. It shows that PST does give citizens public service benefits over and above those provided by the non-PSBs and online-only TV players, and these ‘citizenship’ benefits are highly valued by the public. PST also offers consumers better value for money because the non-PSBs' significantly higher cost per viewer-hour seems unlikely to be compensated for by commensurately higher audience appreciation. The main policy implication is simple: there is no necessary trade-off between citizen and consumer benefits: pound for pound, PST appears to deliver both sets of benefits better than the rest of the market.

scholarly journals Assessment of adaptive capacity of native and adventive species of trees and shrubs in Dnipro region

2021 ◽  
Vol 50 ◽  
pp. 12-21
Author(s):  
I. A. Ivanko ◽  
A. F. Kulik
Keyword(s):  
Invasive Species ◽  
Peroxidase Activity ◽  
Tree Species ◽  
Native Species ◽  
Steppe Zone ◽  
Morus Alba ◽  
Acer Platanoides ◽  
Ulmus Pumila ◽  
Acer Negundo ◽  
Ulmus Laevis

Nowadays, deterioration and loss of ecological functions of urban tree and shrub plantations take place in Europe and, in particular, in Ukraine; it was noted that their number is insufficient to counteract the negative impact of global climate change and protect the population against industrial pollution effects. The issue of resistance of native and adventitious tree species used in the plantations of industrial cities remains relevant; it necessitates the assessment of physiological and biochemical aspects of their adaptation to extreme environmental factors, such as moisture limit in the steppe zone, periodic dangerously low winter temperatures and anthropo-technogenic load (in large urban agglomerations). In order to optimize the assortment of tree species of large megalopolises of the steppe zone of Ukraine and determine their potential resistance to anthropogenic pressures the study was conducted in conditionally clean forest biogeocenoses of the Samara River levee zone and in artificial plantations on the territories located in the coastal zone of the Dnipro River within 1500 m from the Prydneprovskaya thermal electric station (PTES, Dnipro city). It well known that the TPP is the source of atmospheric air pollution by such heavy metals as lead and cadmium. A study of the activity of antioxidant protection enzymes in leaves of native and adventive tree species showed that in the zone of Prydneprovskaya TES impact there was an increase of guaiacol peroxidase activity in Acer platanoides, Ulmus minor, Morus alba; benzidine peroxidase in Acer negundo, Ulmus laevis, Acer platanoides; catalase in A. platanoides, A. negundo, U. laevis, Ulmus pumila and Robinia pseudoasasia. High peroxidase activity, which is complemented by higher catalase activity, indicates the relative resistance of these species to atropo-technogenic pressures supported by antioxidant defense mechanisms. Total chlorophyll content (Chla + Chlb) in leaves of native species Ulmus laevis, Acer platanoides and adventive Morus alba decreased in the zone of TPP impact in relation to conditionally clean areas. The ratio of chlorophyll a to chlorophyll b in contaminated areas significantly increased in leaves of native species Ulmus laevis, Ulmus minor, Acer platanoides compared with control. The invasive species Acer negundo, Morus alba, Ulmus pumila had no significant changes in this indicator. In invasive species such as Ulmus pumila, Acer negundo there was an increase in leaf mass, which may indicate adaptation of these species to anthropogenically altered growth conditions.

scholarly journals SURVIVAL AND GROWTH OF SHELTERBELT TREES AT THREE SPACINGS

1961 ◽  
Vol 37 (3) ◽  
pp. 187-191
Author(s):  
W. H. Cram ◽  
G. A. Morgan
Keyword(s):  
Populus Deltoides ◽  
Maximum Height ◽  
Forest Nursery ◽  
Ulmus Americana ◽  
Acer Negundo ◽  
Caragana Arborescens ◽  
Survival And Growth

Seedlings of Caragana arborescens Lam., Acer Negundo L., Ulmus americana L., Populus deltoides Bartr. and Fraxinus p. lanceolata Sarg. were planted in 3-row shelterbelts at spacings of 4, 8, and 16 feet at the Forest Nursery Station, Indian Head, Saskatchewan. Data for stand and height are presented after 17 years of growth. Survival of caragana, maple, and ash were not materially influenced by Spacing, but that of elm increased from 91 to 100% and of cottonwood from 0 to 25%, as spacings increased from 4 to 16 feet. Caragana was outstanding with 100% survival at all spacings. Maximum height of caragana and ash (15 and 19 feet, respectively) was obtained at the 8-foot spacings; while that of maple and elm (23 and 26 feet) was obtained at the 16-foot spacing.

Early Survival and Growth of Russian Pinus sylvestris L. in Canada

1970 ◽  
Vol 46 (4) ◽  
pp. 325-328
Author(s):  
A. H. Teich ◽  
M. J. Holst
Keyword(s):  
Pinus Sylvestris ◽  
Scots Pine ◽  
High Performance ◽  
Jack Pine ◽  
Stem Form ◽  
Growth And Survival ◽  
Growing Seasons ◽  
Survival And Growth ◽  
Continental Climate ◽  
Better Than

Scots pine provenances from Russia were grown in Ontario at Longlac, Dorset and Chalk River, and in Saskatchewan at Prince Albert and Indian Head. After eight growing seasons in the field all provenances survived well. The three tallest, Orel, Woronesh and Kiev provenances, grew considerably taller than the others, and at Prince Albert, where native jack pine was also grown, the growth and survival of these provenances was also better than that of jack pine. If further studies show that this high performance persists and that stem form is commercially acceptable, seedlings from these three provenances may be useful for reforestation in those parts of Canada with a continental climate.

Physiological and morphological responses of invasiveAmbrosia artemisiifolia(common ragweed) to different irradiances

Botany ◽  
2012 ◽  
Vol 90 (12) ◽  
pp. 1284-1294 ◽  
Author(s):  
Zhong Qin ◽  
Dan Juan Mao ◽  
Guo Ming Quan ◽  
Jia-en Zhang ◽  
Jun Fang Xie ◽  
...  
Keyword(s):  
Leaf Area ◽  
Native Species ◽  
Southern China ◽  
High Growth ◽  
Ambrosia Artemisiifolia ◽  
Total Biomass ◽  
Plant Structure ◽  
Morphological Adaptations ◽  
Net Assimilation ◽  
Disturbed Habitats

Invasion by the exotic herb Ambrosia artemisiifolia L. has become a serious agricultural and environmental problem and of increasing research interest as the species continues its southward spread into subtropical regions of China. To better understand the possible physiological and morphological adaptations of A. artemisiifolia in this region, we conducted a greenhouse experiment using seedlings of A. artemisiifolia and a comparative native species, Urena lobata L. (Caesar’s weed), which is an erect annual shrub in the Malvaceae that commonly co-occurs with A. artemisiifolia in open, disturbed habitats in southern China. Seedlings of both plants were grown under four irradiance regimes (10%, 30%, 55%, and 100% irradiance) from 14 May to 13 July 2010. Ambrosia artemisiifolia showed significantly higher total biomass, total leaf area, specific leaf area, relative growth rate, and net assimilation rate but lower leaf mass fraction than U. lobata at the 30%–100% irradiance levels. With decreasing irradiance, A. artemisiifolia significantly increased biomass allocation to stems and decreased allocation to roots. Meanwhile, A. artemisiifolia exhibited higher light-saturated photosynthetic rates and light saturation points with wide variances except at the 10% irradiance treatment. These findings suggest that A. artemisiifolia has generally higher irradiance plasticity for traits pertaining to biomass partitioning, growth, and plant structure than U. lobata. The ability of A. artemisiifolia to tolerate high shade conditions while maintaining high growth rates at elevated irradiance levels may afford it a competitive advantage and may help explain its recent colonization and spread in southern China.

Sign in / Sign up

Export Citation Format

Share Document